Beneficial Nematodes

Beneficial Nematodes - For Pest Insects

Beneficial nematodes seek out and kill all stages of harmful soil-dwelling insects. They can be used to control a broad range of soil-inhabiting insects and above-ground insects in their soil-inhabiting stage of life. More than 200 species of insect pests from 100 insect families are susceptible to these insect predators.

They are a natural and effective alternative to chemical pesticides, and have no detrimental affect on non-target species such as ladybugs, earth worms and other helpful garden insects.Finally, there is no evidence that parasitic nematodes or their symbiotic bacteria can develop in vertebrates. This makes nematode use for insect pest control safe and environmentally friendly. The United States Environmental Protection Agency (EPA) has ruled that nematodes are exempt from registration because they occur naturally and require no genetic modification by man.

Beneficial nematodes can be applied anytime during the year when soil-dwelling insects are present and soil tempertures are above 45-F during the day. Beneficial nematodes seek out and kill over 200 pest insects in the soil. They are a natural effective alternative to chemical pesticides. Beneficial nematodes are formulated and applied as infective juveniles, the environmentally tolerant free living stage that attacks the insect. Ther are several species and strains that are specialized for particular host insects. It is important to choose the right species for the job. Please review these nematode types for your selection. Steinernema carpocapsae, and Feltiae uses an "ambush" strategy as they wait for an insect host to move by, and therefore works well against pests that are moving around the soil surface. The Heterorhabditids bacteriophora do well against soil pests that are not as mobile because these nematodes are "cruisers", they actively search for hosts deeper in the soil.

Call 520-298-4400 to place order for Beneficial Nematodes shipment to Canada.

Purchase beneficial nematodes from a reputable dealer. All nematodes are not the same. Buglogical nematodes are more tolerant of high tempertures than any other brands. As living organisms, they must be handled properly to remain effective. This helps insure that the nematodes you are buying are still alive. Nematodes do not live very long in storage. Therefore, buying nematodes that are stocked on a store shelf is very risky. Beneficial nematodes from almost any other source may be hauled around the United States from 2 to 3 different companies. It is best to order fresh nematodes and have them delivered directly to you from a reliable source. Other beneficial nematodes may travel an extra 900 to 4,000 miles over 3 to 5 days or more, this will cause high mortality rate before they reach you. Our nematodes are shipped FedEx next day delivery or second day delivery to guarantee live delivery, your choice.

The use of insect parasitic nematodes, and other biological control agents to manage insect pests has grown in popularity. This is primarily due to the changing problems associated with pest control. For example, many pests have developed resistance to certain pesticides, new pests have arisen to replace those successfully controlled, the effectiveness of natural control agents (predators, parasites and pathogens) has been reduced by pesticide use, pesticides are no longer inexpensive to use, and there is increased concern about pesticide safety and environmental quality. These beneficial organisms can be an important component of an integrated pest management (IPM) program for ornamental crops and turf grass sites.

What are beneficial nematodes?

Nematodes are morphologically, genetically and ecologically diverse organisms occupying more varied habitats than any other animal group except arthropods. These naturally occurring organisms are microscopic, unsegmented round worms that live in the soil and, depending on the species, infect plants and animals. The two nematode families Steinernematidae and Heterorhabditidae, contain the insect parasitic nematode species. The most commonly used beneficial nematodes are Steinernema carpocapsae, S. feltiae, and H bacteriophora. Nematodes that are endoparasites of insects attack a wide variety of agricultural pests.

The life cycle of beneficial nematodes consists of eggs, four larval stages and the adults. The third larval stage is the infective form of the nematode (IT). They search out susceptible hosts, primarily insect larvae, by detecting excretory products, carbon dioxide and temperature changes. Juvenile nematodes enter the insect host through the mouth, anus or breathing holes (spiracles). Heterorhabditid nematodes can also pierce through the insect' s body wall. The juvenile form of the nematode carries Xenorhabdus sp. bacteria in their pharynx and intestine. Once the bacteria are introduced into the insect host, death of the host usually occurs in 24 to 48 hours.

As the bacteria enzymatically breaks down the internal structure of the insect, the Steinernematids develop into adult males and females which mate within the insect's body cavity. Heterorhabditids produce young through hermaphroditic females. This form of nematode has the sexual organs of both sexes. As the nematodes grow, they feed on the insect tissue that has been broken down by the bacteria. Once their development has reached the third juvenile stage, the nematodes exit the remains of the insect body.

Biological control for deer ticks - nematodes may have ability to control ticks that spread Lyme disease - Brief Article

By Christine Mlot

Symbiotic microbes and nematodes make a versatile combination that is lethal to a variety of insects found in soil. That combination may now prove useful in controlling not just pests of plants but of people. Researchers from the Department of Agriculture are exploring the use of nematodes in attacking the hard-to-spot ticks involved in the spread of Lyme disease to humans.

At the Agricultural Research Service in Beltsville, Md., parasitologist Dolores Hill has tested Steinernema and Heterorhabditis nematodes for their ability to control adult deer ticks. The nematodes crawl or bite into the tick's body, then release their microbial partners, which infect and kill the tick within 24 hours. "Nematodes are extremely effective" against one stage of the ticks' life cycle, says Hill.

She plans this fall to test woodsy residential areas visited by tick-carrying deer. It may be possible to reduce the numbers of egg-laying female ticks and thus reduce the number of young, disease-transmitting ticks the following spring.

Other USDA researchers are exploring the use of fungi as yet another biological alternative to tick-killing chemical sprays.

Nematode Application: For 50 Mil. and larger quantities. Nematodes packaged in an inert powder carrying material that dissolves in water. Applied one teaspoon of the beneficial nematodes per gallon of water. Application in using a watering can, backpack sprayers, pump sprayers, irrigation systems, hose-end sprayer, or motorized sprayer. After mixing the nematodes with water, use the spray solution immediately. Evenly spray the solution over the ground areas to be treated. Continuous mixing should take place in order to prevent the nematodes from sinking to the bottom of the container. Keep the soil slightly moist during the first 7 days after application to help establish the nematodes in the soil. Sprinkle the turf or soil again with water after the application of the nematodes. Apply nematodes as soon as possible for best product performance. You may keep the package of nematodes in the refrigerator for up to 3 weeks upon receiving the product. Nematode Application: For 10 Mil. Nematodes packaged on a sponge. Place the entire sponge in a bucket add two quarts of water, squeeze sponge for a few minutes to get the nematodes out of the sponge. Discard the sponge and pour the bucket of water into a sprayer or watering can. Add another gallon of water to dilute the nematodes and to make up the volume for your sprayer. The 10 Mil. Nematodes can only be kept for up to 3 days in refrigeration.

Beneficial Nematodes

Quick Facts

Insect parasitic beneficial nematodes are small round worms that kill insects but are harmless to other organisms.

Several species of these nematodes are developed as biological insect controls.

Among the pests effectively controlled are most turf insects and several other insects that live in soil.

The beneficial nematodes are small, round worms that complete part of their life cycle in insects. Several species can kill insects in this process, and some are marketed as a biological control agent.

The use of insect parasitic nematodes to control soil insects, including many turf grass and Garden pests, has received increased attention in recent years. Insect parasitic nematodes are also known as predator nematodes, beneficial nematodes or entomogenous nematodes. Insect parasitic nematodes have been studied for potential biological control of turf pests for more than 50 years. However, their increasing availability and rising public demand for alternatives to insecticides has heightened interest in beneficial nematodes. Two types of beneficial nematodes have been most actively considered for control of insect pests. Steinernema has been thoroughly researched, including control studies for Japanese beetle conducted in the 1930s. Recent attention has shifted to include the genus Heterorhabditis. Both groups are in the order Rhabdita, the bacteria-feeding nematodes. It includes a large number of common but frequently overlooked soil-infesting nematodes that assist in organic matter breakdown.

Life Cycle of Beneficial Nematodes

Beneficial nematodes are mobile and move short distances in search of host insects. Heterorhabditis is more mobile than Steinernema. Nematodes use carbon dioxide and perhaps other chemicals produced in waste products of insects as cues to find their hosts. Upon entering the insect the nematodes kill their host by releasing bacteria into it, strains of Xenorhabdus species that are associated with the nematode. The bacteria develop within the body cavity of the susceptible host. The host dies from blood poisoning within a few days.

The dead insect generally maintains its original shape and does not decay in a normal manner because its body is filled with these specialized bacteria. Associated color changes may occur. For example caterpillars and grubs parasitized by Heterorhabditis may have a reddish-brown color. The nematodes develop by feeding upon the bacteria and degraded host tissues.

The active stage of the nematode that invades an insect is the juvenile (dauerlarva) stage. These infective juveniles are applied for insect control. Steinernema nematodes enter the insect through natural openings, such as the mouth, spiracles and , then penetrate into the body cavity. Heterorhabditis nematodes use natural openings but also can enter by piercing the body wall.

Once inside the infected insect, nematodes develop rapidly, in five or more days, depending on host quality and temperature. Normally, one to two generations occur in a host insect. Thousands of nematodes can be produced following a single infection. Ultimately, the body wall of the dead host insect ruptures and releases the nematodes. The beneficial nematodes typically kill their host insect within two to three days after invading the body cavity.

References:

Bedding, R.A. and L.A. Miller. 1981. Use of a Nematode, Heterorhabditis heliothidis to Control Black Vine Weevil, Otiorhynchus sulcatus, in Potted Plants.Ann.Appl.Biol. 99:211-216.